DDT Exposure Linked with Alzheimer's Disease

DDT exposure could increase the risk and severity of Alzheimer's disease in some people, according to a latest study.

Dichlorodiphenyltrichloroethane (DDT) was developed in the 1940s and was widely used to fight malaria, typhoid and even lice.  The United States banned the chemical in 1972 after research showed that it caused adverse environmental effects.

But, the toxin is still used in several countries. Also, the pesticide takes years to break down, which is why several people in the U.S still have considerable levels of DDT and its broken-down product, DDE, in their blood.

In the present study, researchers at Rutgers University found that DDE levels are high in late-onset Alzheimer's disease patients when compared to other people.

In the present study, researchers collected blood samples from 86 Alzheimer's disease patients and 79 people without a history of dementia. They found that DDE levels in 74 test patients were about four times higher than that in the control group.

Also, patients with a version of ApoE gene (ApoE4), which is associated with a greater risk of AD along with high levels of DDE in blood, had severe cognitive problems than other patients.

Researchers then looked at the brain cells of the patients and found that DDE/DDT exposure was linked with amyloid protein accumulation. Amyloid proteins contribute to cognitive loss by disrupting key regions of the brain.

"We need to conduct further research to determine whether this occurs and how the chemical compound interacts with the ApoE4 gene" said Jason R. Richardson, associate professor in the Department of Environmental and Occupational Medicine at Robert Wood Johnson Medical School, in a news release.

The study is published in the journal JAMA Neurology.

About 70 to 80 percent of people who took part in a survey by Centers for Disease Control and Prevention had significant levels of the pesticide in the blood. A related research published in the journal Environmental Health Perspectives had also linked DDT exposure in womb to high blood pressure in women.